lightoj 1029

生成树

代码如下：

#include <bits/stdc++.h>using namespace std;int mat[2][110][110];const int inf = 1e9;int vis[110], dis[110], n;int dij(int dex){    memset(dis, 0x3f3f3f, sizeof(dis));    memset(vis, 0, sizeof(vis));    dis[0] = 0;    int ret = 0;    for(int i = 0;i <= n;i++)    {        int u = -1, mi = inf;        for(int j = 0;j <= n;j++)            if(!vis[j] && dis[j] < mi)        {            mi = dis[j];            u = j;        }        if(u == -1)        break;        ret += dis[u];        vis[u] = 1;        for(int j = 0;j <= n;j++)        {            if(!vis[j] && dis[j] > mat[dex][u][j])                dis[j] = mat[dex][u][j];        }    }    return ret;}int main (){    int t, cnt = 1;    scanf("%d", &t);    while(t--)    {        scanf("%d", &n);        int u, v, w;        memset(mat, 0x3f3f3f, sizeof(mat));        while(scanf("%d %d %d", &u, &v, &w), u || v || w)        {            mat[0][u][v] = mat[0][v][u] = min(mat[0][u][v], w);            mat[1][u][v] = mat[1][v][u] = min(mat[1][u][v], -w);        }        int ans = dij(0) + (-dij(1));        printf("Case %d: ", cnt++);        if(ans%2) printf("%d/2\n", ans);        else  printf("%d\n", ans/2);    }    return 0;}